How we use angiopoietin-2 in the diagnosis and management of vascular anomalies.

The diagnosis of vascular anomalies remains challenging due to significant clinical heterogeneity and uncertain etiology. Evaluation using biopsy and/or genetic testing for somatic variants is invasive, expensive, and prone to sampling error. There is great need for noninvasive and easily measured blood laboratory biomarkers that can aid not only in diagnosis, but also management of treatments for vascular anomalies. Angiopoietin-2, a circulating blood angiogenic factor, is highly elevated in patients with kaposiform hemangioendothelioma with Kasabach-Merritt phenomenon and kaposiform lymphangiomatosis. Here, we describe our clinical experience using serum angiopoietin-2 as a biomarker for diagnosis and monitoring response to treatment.

Kaposiform lymphangiomatosis treated with multimodal therapy improves coagulopathy and reduces blood angiopoietin-2 levels.

Kaposiform lymphangiomatosis (KLA) is a rare, life-threatening congenital lymphatic malformation. Diagnosis is often delayed due to complex indistinct symptoms. Blood angiopoietin-2 (ANG2) levels are elevated in KLA and may be useful as a biomarker to monitor disease status. We report a 7-year-old male child with easy bruising, inguinal swelling, and consumptive coagulopathy, diagnosed with KLA. A multimodal treatment regimen of prednisone, sirolimus, vincristine, and adjunctive zoledronate was used. Plasma ANG2 levels were highly elevated at diagnosis but decreased during treatment. The patient showed significant clinical improvement over a 38-month period and normalization of ANG2 levels correlated with resolution of the coagulopathy.

Upper arm life-saving amputation of a 12 day-old neonate due to extensive vascular tumor of the upper extremity.

Vascular tumors in neonates are mostly benign; however, locally aggressive voluminous forms may destabilize the hemodynamics of a neonate. Herein, we present an unusual case of a neonatal giant vascular tumor in the right upper extremity, causing a consumption coagulopathy and acute deterioration of vital signs. The patient required mechanical ventilation, inotropic support, and administration of blood products by the seventh day. Vascular embolization attempts failed to improve the general condition of the patient. Due to the deteriorating and life-threatening general condition of the patient, amputation around the upper arm level occurred under emergency conditions on the twelfth day. The patient's hemodynamic parameters were regained immediately, with neither inotropic agents nor blood products required after the second postoperative day. Clinical and pathological diagnosis revealed kaposiform hemangioendothelioma. Patient monitoring proceeded until the age of 15 months, with no local recurrence around the stump or soft tissue coverage complications. Therefore, since other treatment options failed, the early amputation decision was life-saving.

Development of Kasabach-Merritt phenomenon following vaccination: More than a coincidence?

Kasabach-Merritt phenomenon (KMP) occurred uniquely in patients with kaposiform hemangioendothelioma (KHE) and tufted angioma (TA). We report the clinical characteristics of two patients with KHE involving the right upper arm. The patients demonstrated rapid enlargement of the lesion with severe KMP shortly after vaccination. Sirolimus was used to treat the KHE with KMP. The patients showed a quick normalization of the platelet level. The follow-up examination revealed that the size of the mass was significantly decreased. This report raises the intriguing possibility that extrinsic factors may contribute to the development of KMP in the context of an already existing KHE.

Kaposiform hemangioendothelioma with Kasabach-Merritt phenomenon in an infant: Successful treatment with prednisolone, vincristine, and addition of sirolimus.

A full-term newborn with kaposiform hemangioendothelioma (KHE) affecting the right thigh with thrombocytopenia due to Kasabach-Merritt phenomenon (KMP) was referred to our center. After biopsy, he rapidly evolved to severe thrombocytopenia and severe coagulopathy. Standard therapy was initiated with prednisolone and vincristine. His coagulopathy worsened to life-threatening hemorrhage necessitating aggressive blood products replacement. Sirolimus was added; he became transfusion independent with no further bleeding and reduction in tumor size. Addition of sirolimus to treatment of vascular anomalies with hemostatic complications should be considered as part of early treatment for patients with KMP/KHE.

Successful management of steroid-resistant vascular tumors associated with the Kasabach-Merritt phenomenon using sirolimus.

Vascular tumors associated with Kasabach-Merritt phenomenon (KMP) are life-threatening and the mortality is as high as 10-30%. Steroids are considered the primary choice for drug therapy. However, there are many steroid-resistant cases. In the present study, analyzed data are presented to support the use of sirolimus in clinical practise for the treatment of corticosteroid-resistant vascular tumors with KMP in eight infants between June 2015 and April 2017 in a single hospital. The time to initial response was 6.8 ± 2.7 days. The average stabilization time for the platelet count was 19.1 ± 8.5 days. At the time of publication, the average duration of sirolimus treatment was 14.1 ± 4.0 months, and the average time for sirolimus treatment as a single agent was 12.6 ± 4.2 months. The side-effects were tolerable and included oral ulcer, fever, pain, skin rash and transient ascension of serum transaminase and cholesterol. Our study indicated that sirolimus therapy is an effective and safe method for the treatment of corticosteroid resistant vascular tumors associated with KMP in infants.

Giant liver hemangioma with adult Kasabach-Merritt syndrome: Case report and literature review.

RATIONALE: Adult Kasabach-Merritt syndrome associated with giant liver hemangioma is rare; to date, most reports have been single-case reports, and no multi-case reports or literature reviews are available. DIAGNOSES: We conducted a retrospective analysis of 5 cases of adult Kasabach-Merritt syndrome associated with giant liver hemangioma treated at our hospital between 2011 and 2016. All 5 patients had varying severities of leukopenia, anemia, thrombocytopenia, prolonged prothrombin time, and hypofibrinogenemia. INTERVENTIONS: All the patients underwent surgery: 2 patients had left hemihepatectomy; 1 had enucleation; 1 had a right hemihepatectomy; and 1 had a left trisectionectomy. OUTCOMES: The 5 patients had an average operative time of 6.9 hours and an average blood loss of 3200 mL. One patient developed a biliary fistula (grade II) after the operation. There was no mortality among 5 patients. The white blood cell counts, hemoglobin, platelets, and prothrombin times of all 5 patients returned to normal after the operation. To date, a total of 11 cases of adult Kasabach-Merritt syndrome associated with giant liver hemangioma have been reported, of which 8 patients underwent surgery, and their platelets and coagulation returned to normal after the operation. LESSONS: Adult Kasabach-Merritt syndrome associated with giant liver hemangioma is uncommon, and surgical treatment is risky. However, resection of the tumor corrected the abnormalities in hematological and coagulative systems.

Treatment of Corticosteroid-Resistant Vascular Tumors Associated with the Kasabach-Merritt Phenomenon in Infants: An Approach with Transcatheter Arterial Embolization Plus Vincristine Therapy.

PURPOSE: To investigate the effectiveness and application of transcatheter arterial embolization (TAE) plus systemic vincristine for treatment of corticosteroid-resistant vascular tumors associated with Kasabach-Merritt phenomenon in infants. MATERIALS AND METHODS: TAE was performed in 17 infants (average age, 4.3 mo ± 2.4; range, 1-10 mo) with corticosteroid-resistant vascular tumors associated with Kasabach-Merritt phenomenon, followed by intravenous vincristine once weekly for systemic chemotherapy. The effects and complications were observed and evaluated after a cycle (1 cycle: TAE plus treatment with vincristine every 4 weeks). Cycles were repeated in infants with platelet counts < 150 × 10(9)/L. RESULTS: In 17 patients, 36 treatment cycles were successfully performed. The platelet count for all patients increased to ≥ 100 × 10(9)/L for the first time at 6.0 days ± 3.5; the platelet level of 15 infants was maintained at levels > 150 × 10(9)/L at 57.5 days ± 16.5. Before treatment, two infants had a normal fibrinogen level (2.21 g/L and 2.34 g/L); the fibrinogen level in the other 15 infants was first found to be increased to ≥ 2.0 g/L at 7.0 days ± 3.4 and was stabilized at levels > 2.0 g/L at 55.9 days ± 13.8 after treatment. Complications were graded as major in four cases and as minor in 13 cases. CONCLUSIONS: TAE plus vincristine can rapidly improve levels of platelets and fibrinogen, and it is an effective method for treatment of corticosteroid-resistant vascular tumors associated with Kasabach-Merritt phenomenon in infants.

Kaposiform Haemangioendothelioma-spectrum Lesions with Kasabach-Merritt Phenomenon: Retrospective Analysis and Long-term Outcome.

Kasabach-Merritt phenomenon (KMP) is a rare life-threatening vascular condition of infancy. Prognosis factors and long-term follow-up data are lacking. We retrospectively analysed the records of 24 infants (10 females, 14 males) treated for KMP in the Department of Dermatology of Necker-Enfants Malades Hospital, Paris, France, from 1984 to 2012. Mean duration of thrombocytopaenia (2,000-38,000 platelets/mm3, mean 10,500/µl) was 8.8 months (range 3 days-84 months), which correlated with tumour infiltration depth on imaging. D-dimer levels were always elevated, even before KMP onset. Each patient received a mean of 4.8 different treatments (range 1-10). Median follow-up was 6.5 years (range 2 months-22 years). All infants had residual cutaneous lesions, along with inflammatory manifestations (n = 9), elevated D-dimer (n = 5) and orthopaedic sequelae (n = 5). The permanent coagulopathy (elevated D-dimer) even after resolution of KMP suggests the presence of chronic low-grade platelet trapping, with possible sudden worsening, and raises the possibility of prophylactic anti-platelet therapy.

[Comprehensive therapy for infant vascular tumor associated with Kasabach-Merritt phenomenon].

OBJECTIVE: To summarize the management of infant vascular tumors with Kasabach-Merritt phenomenon (KMP) and to evaluate the effect of drug combined with sclerotherapy. METHODS: From Feb. 2007 to Nov. 2014, 25 cases with KMP, who underwent drug therapy combined with sclerotherapy, were retrospectively studied. Oral corticosteroids (2 mg/kg per day) was used as the first-line therapy on all of the patients and intravenous vincristine (1.5 mg/m2 every week) was added when the platelet counts didn't recover obviously after 2-3 weeks. After the recovery of the platelet counts, the patients were admitted for sclerotherapy (average, 4.56 sessions per case) with 100% alcohol (1-3 ml per session), Lauromacrogol (1.25-5 ml per session) and betamethasone (0.25-1 ml per session). All the patients were followed up for 42 months ( range, 9 months to 6.5 years). Therapeutic outcomes were assessed by evaluating platelet counts, size of lesion, function of trunk and limb. RESULTS: All the 25 cases got obvious recovery in the platelet counts [average, (94.3 ± 18.5) x 10(9)/L] after drug therapy, of which 16 were treated by single oral corticosteroids for 4-7 weeks and 9 were treated by corticosteroids plus intravenous vincristine for 2-5 weeks. Meantime, 11 cases received platelet transfusions, of which 3 were coupled with gamma globulin intramuscularly. During the first admission, each of the 25 cases received 1-4 sessions of sclerotherapy (average, 2.6 sessions each case). One week after the sclerotherapy, the platelet counts returned to (167-312) x 10(9)/L (average, (258.5 ± 34.4) x 10(9)/L). The hemoglobin and blood coagulation function returned to normal within 1-5 weeks. Meanwhile the mental condition, appetite, body weight, sleeping were greatly improved. The size of the lesions decreased gradually after the combined therapy including 13 cases within 3-12 months and 13 cases within 13-36 months. Long term follow-up indicated that only 1 case need treatment for recurrent decrease of platelet counts, and all of the 25 cases kept the normal weight, height, immunity as well as the growing development. CONCLUSIONS: Oral corticosteroids plus intravenous vincristine combined with sclerotherapy is a reliable management with high cure rate, short course and minor side-effect.

Refractory Kasabach-Merritt phenomenon successfully treated with sirolimus, and a mini-review of the published work.

Kasabach-Merritt phenomenon (KMP) is a rare and life-threatening disease involving a vascular tumor combined with severe consumptive coagulopathy. We present for the first time a case of KMP with the vascular tumor involving two anatomical sites; the patient failed to respond to steroids and vincristine. Following sirolimus therapy at a dose of 0.8 mg/m(2) twice daily, the lesions shrank and the platelet count improved and remained normal 4 months after initial therapy. Current treatments for KMP are not particularly effective. Sirolimus at 0.8 mg/m(2) per dose, administrated twice daily, appears to be a safe and effective management option. It appears to be an interesting therapeutic option in refractory KMP, but the time to response is variable.

Steroid-resistant kaposiform hemangioendothelioma: a retrospective study of 37 patients treated with vincristine and long-term follow-up.

BACKGROUND: Kaposiform hemangioendothelioma (KHE) with Kasabach-Merritt phenomenon (KMP) still remains a particular and life-threatening disease. The purpose of this study was to evaluate the efficacy of vincristine (VCR) and the possibility of replacement with steroids in the treatment of steroid-resistant KHE with KMP. PROCEDURE: We retrospectively reviewed the medical records of 37 patients with steroid-resistant KHE who were treated at the Children's Hospital of Fudan University between March 2003 and March 2013. RESULTS: The age of initial diagnosis with KHE was between 1 day and 10 months. Eight and 29 cases were located in the superficial and deep soft tissues, respectively. Thirty-seven KHE lesions did not respond well to steroids before starting VCR treatment. Twenty-six KHE lesions achieved complete remission, with platelet counts reaching normal levels within7.6 ± 5.2 weeks after VCR treatment. The vascular tumor began to decrease in size or soften at an average of 4.9 ± 2.7 weeks. Two KHE lesions had partial responses and one remains in treatment. Eight KHE lesions had no apparent response to VCR and thus received other therapies. Twenty-eight patients have ended treatment with VCR; the average length of treatment was 31.2 ± 5.9 weeks. Side effects occurred in 48.6% of patients who received steroids, and in 11.4% of patients who received VCR treatment. The mean follow-up time was 3.5 years. No recurrences have been reported. CONCLUSIONS: VCR appears to be a safe and effective treatment option in the management of steroid-resistant KHE with KMP, and recommended as first-choice treatment.

Hand-assisted laparoscopic splenectomy for a huge splenic vascular lesion with aneurysms in a patient with impending Kasabach-Merritt syndrome-like phenomenon.

Splenic vascular lesions are relatively rare and are usually found incidentally. However, the vascular lesions associated with Kasabach-Merritt syndrome, such as hemangioma, can be life-threatening. We herein describe the case of a young adult female patient with a huge splenic vascular lesion, aneurysms of the splenic artery, and increased plasma levels of fibrin/fibrinogen degradation products and D-dimers. Hand-assisted laparoscopic splenectomy was performed, after which the coagulopathy was drastically improved. Minimally invasive surgical intervention such as hand-assisted laparoscopic splenectomy should be considered as the first treatment choice in such a case.

Kaposiform hemangioendothelioma complicated by Kasabach-Merritt phenomenon: ultrastructural observation and immunohistochemistry staining reveal the trapping of blood components.

Kaposiform hemangioendothelioma (KHE), a borderline tumor of endothelial origin, is associated with Kasabach-Merritt phenomenon, characterized by profound thrombocytopenia and consumptive coagulopathy resulting from the localized intravascular coagulation (LIC) in the tumor. Previous studies have suggested that the trapping of blood components, including platelets, may underlie the LIC in KHE. However, more evidence is needed to support this hypothesis. In this study, one case of a Chinese infant with a KHE in the left arm was complicated by Kasabach-Merritt phenomenon. The tumor was partially resected and the sample was used for ultrastructural observation and immunohistochemistry staining of Glut-1. Ultrastructural observation found the trapping of erythrocytes, platelets, macrophages, and lymphocytes in the slit-like channels of the tumor nodules, and phagocytic vesicles in the cytoplasm of neoplastic cells. Immunohistochemistry staining further showed numerous Glut-1(+) erythrocytes in the channels. In conclusion, our results provided compelling morphological evidence of the trapping of blood components in KHE, which may interpret the LIC in the tumor and subsequent consumptive coagulopathy.

Long-term outcome of vincristine-aspirin-ticlopidine (VAT) therapy for vascular tumors associated with Kasabach-Merritt phenomenon.

BACKGROUND: . This study aimed to clarify the combinatorial treatment effect of agents as aspirin and ticlopidine associated with vincristine in the management of Kasabach-Merritt phenomenon (KMP), a severe thrombocytopenic coagulopathy that occurs in the presence of an enlarging vascular tumor such as kaposiform hemangioendothelioma (KHE) and tufted angioma (TA). PROCEDURE: . A retrospective review was conducted of medical records of all children with diagnosis of KHE or TA associated with KMP treated with vincristine-aspirin-ticlopidine (VAT) therapy at two different institutions in the same country from 1994 to 2011. Clinical features, response to VAT therapy and outcomes were recorded. RESULTS: . Eleven patients (mean age 11 months, range 0-36), including seven females (64%) and four males (36%), were identified. Seven patients underwent incisional biopsy and two different histologies were found, KHE in four patients and TA in three patients. Tumors were located in the head and neck (n = 5), chest wall (n = 2), arm (n = 2) and retroperitoneum (n = 2). Mean platelet level was 10,200/mm(3) (range 4,000-21,000). A plaque-like lesion with ecchymosis was the most common cutaneous manifestation (63%). All patients underwent VAT therapy. Mean duration of treatment was 3.9 months for vincristine, 13.9 months for aspirin, and 13.4 months for ticlopidine. All patients are alive with a mean follow-up of 4.5 years (range, 2-17). CONCLUSIONS: . Antiaggregant therapy is helpful in combination with vincristine in the treatment of KMP associated with KHE and TA. Prognosis is excellent if severe thrombocytopenia is controlled despite failure in reduction of tumor size.

Kasabach-Merritt phenomenon: a report of 11 cases from a single institution.

BACKGROUND: Kasabach-Merritt phenomenon (KMP) is a rare condition and optimal treatments have not yet been established, especially for cases that are unresponsive to first-line therapy. We retrospectively reviewed 11 KMP cases treated over the past 13 years in our institute. OBSERVATIONS: With the exception of 1 case, steroids were administered as the first-line therapy. Eight cases required second-line or third-line therapy. The effective salvage therapies include interferon (n=1), radiotherapy (n=1), and chemotherapy (n=5). One case continues to depend upon chemotherapy. Three refractory cases were therapy dependent over 1 year of age, whereas 8 were treated effectively by 6 months of age. CONCLUSIONS: Chemotherapy seems to be the most effective therapy for steroid-resistant KMP cases.

Kaposiform hemangioendothelioma with Kasabach-Merritt phenomenon: successful treatment with embolization and vincristine in two newborns.

Kaposiform hemangioendothelioma (KHE) is a rare vascular tumor and has a high mortality in newborns when associated with Kasabach-Merritt syndrome (KMS). In two newborns with KHE and severe KMS refractory to medical treatment, emergency embolization led to clinical improvement in the acute neonatal setting by reducing tumor volume, increasing the platelet count, and improving other clotting parameters. Systemic vincristine treatment was added for further tumor control. Both patients remained symptom-free at long-term follow-up.